A recent national study about the effectiveness of Echinacea in cold treatments was performed by a medical school in Kansas City. The results stated that 22.5% of the randomly chosen 250 adult subjects in the placebo group in the study noted that their treatment appeared to shorten the length of their colds. The implied population in this study is a. All people taking Echinacea to treat their cold b. All the randomly chosen adult subjects in the study described c. All adults in United States d. All medical schools testing the effectiveness of Echinacea The implied sample in this study is a. All people taking Echinacea to treat their cold b. All the randomly chosen adult subjects of the placebo group in the study c. All adults in United States d. All medical schools testing the effectiveness of Echinacea The descriptive statistic of interest in this study is_____________. The study would be categorized as: (select ALL that apply) a. experimental b. cross sectional c. observational d. retrospective e. prospective Would the value of 22.5% described above be considered a parameter or a statistic? Why?